Somatomedin C-binding and action in fibroblasts from aged and progeric subjects

C. A. Conover, L. A. Dollar, Ronald (Ron) Rosenfeld, R. L. Hinz

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12 Scopus citations


Aging is associated with diminished cell growth, which has been ascribed in part to decreased cellular responsiveness to serum mitogens. To investigate whether there is an age-related loss of responsiveness to somatomedin-C (SM-C), we studied SM-C binding and action in early passage fibroblasts from normal donors, aged 7-96 yr, and one progeric subject. SM-C stimulated [3H]thymidine incorporation 4- to 16-fold in young cells, 4- to 17-fold in aged cells, and 4- to 11-fold in progeric cells. SM-C was synergistic with 0.25% human hypopituitary serum in stimulating [3H]thymidine incorporation in all cell lines. Dose-response curves for SM-C stimulation of thymidine incorporation were not significantly altered in aged or progeric cells. Half-maximal responses occurred at 5-15 ng/ml SM-C for all cell lines. [3H]Thymidine incorporation results were supported by cell replication studies. In addition, binding of [125I] SM-C was virtually identical in all cell lines, with 50% displacement at 2-5 ng/ml SM-C. Thus, in vivo aging does not appear to be associated with either an alteration in SM-C receptors or a diminished cellular responsiveness to SM-C's mitogenic effects.

Original languageEnglish (US)
Pages (from-to)685-691
Number of pages7
JournalJournal of Clinical Endocrinology and Metabolism
Issue number4
Publication statusPublished - 1985
Externally publishedYes


ASJC Scopus subject areas

  • Biochemistry
  • Endocrinology, Diabetes and Metabolism

Cite this

Conover, C. A., Dollar, L. A., Rosenfeld, R. R., & Hinz, R. L. (1985). Somatomedin C-binding and action in fibroblasts from aged and progeric subjects. Journal of Clinical Endocrinology and Metabolism, 60(4), 685-691.